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Best Subject Lines to Increase Your Open Rate

email subject lines tips

Email marketing has become one of the most-used marketing tools for lead generation, communication, and general revenue increase. But with the increased popularity also came plenty of strategies on how to make sure your customers actually open your emails in the first place. Smart Insights reports claim that the average open rate can range anywhere from 5% to 25% depending on the size of your business and its industry.

But what really makes people open emails is their subject line.

Writing the right subject lines is tricky. You need to make sure it hits just the right spot. Very rarely is a subject line created in just a couple of seconds. A good subject line provokes an emotion or a curiosity that your subscriber can’t resist.

How to create email subject lines that get opened?

The best way to write awesome subject lines for higher open rates is by leveraging natural human tendencies and emotional triggers. Here are a few ways to use these in your subject lines.

  • Add elements of scarcity (limited availability) or urgency (limited time) to increase FOMO (fear of mission out).
  • Ask a question (and answer it in your email), promising something interesting (like a surprise) to stimulate the reader’s curiosity.
  • Add humor to create a good first impression.
  • Use vanity to increase open rates. Promise something that makes the subscriber look better to their peers
  • Ask the who, what and why to understand who your customer is, in order to personalize your email.

Most common email types include:

  • Welcome emails;
  • Offers;
  • Abandoned cart;
  • Announcements;
  • Weekly / monthly newsletters.

Once you establish what your email will be about and write the content, you’ll be able to assess the subject line that will give you the best results.

What kind of subject lines people like?

So now that you have established who are you writing to and your email type, you can select the reaction you want to install.

Digital Marketer notes that there are eight types of subject lines audience tends to react to best. They include things like self-interest, curiosity, news, social proof, humanity, story, scarcity, and offer.

Another way of doing this is look at your past headlines and see what worked – based on the email and reaction type, analyze why your audience reacted to certain subject lines better than others.

The must-have elements of best subject lines

Powerful words

The email marketing world is full of emotion-evoking words. Words such as ‘epic’, ‘fail’, ‘everything’, ‘important’ and ‘inspire’ are able to bring out a certain curiosity in people that will make them want to know what’s happening within your email. And that’s another click for you! Try to stir emotions in people in your subject lines but make sure you don’t look spammy Some spam filters are looking at subject lines on emails and if they look similar to other emails people mark as spam, they can get caught in spam filter!.

The value word

Each email needs to have a value. That value should be summarized in a single word, which you need to add to your subject line. For example, that can include guides, facts, planners, offer, discount, sale, and so on. Your email should always include the value you’re bringing to your customer.


Using numbers will help people skim through what the email will be about. The number can also directly correlate with the value you’re giving your customer and increase your opening chances. To learn more about how numbers can influence your subject lines, we recommend reading studies on psychological pricing – the same principle applies to using numbers in your headlines.

Using emojis (optional)

Marketers have started adding emojis after noticing they’re most used in casual online conversation. Strategically using emojis will help you create a relatable subject line that will make people want to open your email and as a bonus point, let them have a giggle or two and will also usually stand out in a crowded inbox. Of course, using emojis is optional as it depends on your own personal brand and tone of voice.

10 best email subject lines for open rates

  • Everything you need to know about [insert value]
  • Here’s what we think about [insert value]
  • [Insert Number] templates to boost your [insert value]
  • Okay [First Name], we need to talk 🤔
  • From rags to riches – here’s [insert a name]’s story
  • Uh-oh, your [insert value]  is expiring
  • Last Day To See What This Mystery Email Is All About
  • How to email a busy person (including a word-for-word script)
  • Steal these email templates…
  • So I’ll pick you up at 7?

10 best email subject lines for click-through rate

  • [insert number] hacks to inspire your [insert value]
  • Hey [First Name], join us at [insert value]
  • [insert value] vs [insert value] – the battle is on 💪
  • Become a [insert value]
  • Two razors for your friends (on us)
  • Since we can’t all win the lottery…
  • TOP SECRET beauty tricks
  • Get a head start on summer upon sign up
  • Truth or Dare? Show us what you got [First name]
  • Last opportunity to join us [First name]

10 most effective subject lines for selling online

  • Get your [insert value] today for [insert number] less 💡
  • [First Name], Get free shipping today only
  • Since you asked, here is [insert number] discount
  • Everything [insert number] cheaper only for today
  • FREE gift with your next order!
  • Flash. Sale. Alert.
  • [Insert number] off your favorites
  • Hey, forget something? Here’s [insert number] off.
  • Happy birthday, here’s our gift for you!
  • Still thinking about it? Offer expires tonight

Of course, subject lines depend on your own content, industry, and further marketing trends. But if you’re not satisfied by your ROI and the numbers you’re getting, try experimenting with new subject lines and the elements we gave you and see what happens.


While most email marketing platforms allow you to use A/B testing to test your own audience, companies like Mailigen also let you run your headlines through the subject line advisor and help you create a campaign that will give you the best open rates.

We’d love to hear your thoughts on what it takes to create the best subject line, so make sure you let us know what you think in the comments below.

Best Subject Lines to Increase Your Open Rate
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    March 20, 2018 at 9:27 am

    A really nice & informative post you have shared here. Nice subject lines you have shared here. Subject lines are the main point which will attract & describe all the things which written in the mail. Recently I have purchased a bulk email list from & they suggested me to use trendy & attractive subject lines for email send.
    Thank you

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